Taxonomic Notes
Some well-structured clades have been genetically and morphologically identified (for a review see Carranza et al. 2008). The subspecies Chalcides bedriagai pistaciae is sometimes considered to be a valid species, but evidence for this is lacking (J. Pleguezuelos pers. comm.). It is treated here as a junior synonym of a monophyletic Chalcides bedriagai.
Justification
Bedriaga's Skink is endemic to the Iberian Peninsula and some adjacent small islands. It is assessed as Least Concern because, while this species is probably in significant decline (but probably at a rate of less than 30% over ten years) in some well-studied parts of its range, it remains widespread and can be abundant in much of mainland Iberia.
Geographic Range Information
This species is endemic to the Iberian Peninsula. It occurs widely in Spain (except the north) and Portugal, but is extremely patchy in its distribution and appears to be absent from many areas. Pollo (2015) suggests that this is probably a consequence of undersampling rather than true absence. It is found on the Atlantic islands of Islas Cíes, Ilha do Pessegueiro, Isla de Ons (from which there are however no recent records; Pollo 2015), and Isla de Sancti Petri, and is present on the Mediterranean islands of Islas del Mar Menor and Isla de Nueva Tabarca. It is found from sea level to 1,750 m asl.
Population Information
It can be quite abundant in areas of good ground cover, but in some areas can occur in extremely low densities (Pino-Pérez et al. 2014, who report a density of 10 individuals/km2 in Barra dunes which they suggest reflects the harsh conditions at the limit of the species' range combined with the impacts of development and habitat fragmentation). In a number of areas from which density estimates over time are available, the species appears to be in decline. The highest known density is 151 individuals /ha, at a site where density was observed to decline to 99 indi/ha over a period of five years (Serantes and Galán 2007). Between 1984-1986 and 1995-1996 a Galician subpopulation declined from 18 ind./ha to 1.3 ind./ha (Galán 1999).
It appears to be less common in inland than coastal areas, where it is locally abundant only in a number of mid-montane areas (Pollo 2015). The species has not been recorded from towns in Sierra Naciente, San Roque or Areamilla since the mid-1990s (Pino-Pérez et al. 2014). It seems to be in decline on the Cíes islands and may be extinct on Ons, where surveys described as "recent" by Pollo (2015) have failed to record it.
Habitat and Ecology Information
This skink occurs in a variety of both dry and humid habitats, but is "perhaps more typical" of relatively moist environments (Speybroeck et al. 2016), especially where it occurs outside the Mediterranean climatic zone (Pino-Pérez et al. 2014). It is found in areas from sandy lowland areas, including sand dunes, to agricultural land and areas with dense herbaceous growth, rocky hillsides, and partially forested stream valleys (Speybroeck et al. 2016). Suitable habitats tend to be characterised by large numbers of potential shelter sites, including rocks, logs or human garbage (Speybroeck et al. 2016). In heavily modified areas the latter can form an important proportion of shelter sites (Pino-Pérez et al. 2014). The females give birth to one to six fully formed young between May and August (Speybroeck et al. 2016). It is active between April and September in the north of the range and may have a longer activity period further south (Speybroeck et al. 2016). Animals reach sexual maturity in their second or third year of age in the northwest of the range (Pollo 2015).
Threats Information
Modification of habitat, especially in coastal regions, has led to localised declines in this species. It may be at risk in urban centres due to the development of areas with suitable soils, restricting the species to small isolates in less suitable habitats (Pino-Pérez et al. 2014). It is impacted in both insular and continental regions by fire and by urban development, including that driven by migration and tourism (Pino-Pérez et al. 2014). These authors estimate that human population densities greater than 500 ind./km2 are likely to represent a threat to this species due to both the direct impacts of development and associated increases in human waste and land use change It is also probably affected by the impact of increasing wild boar (Sus scrofa) populations. Remnant subpopulations in developed coastal areas may be at risk from the expansion of bindweed, which causes the loss of native dune vegetation (Pino-Pérez et al. 2014). It could potentially be lost from a large area due to relatively small-scale habitat alterations, due to its contagious (clustered) distribution in coastal areas, and the sensitivity of island subpopulations to disturbance (Pollo 2015). One beach subpopulation underwent a documented decline between 2002 and 2006 as a result of habitat alteration during work cleaning up an oil slick (Pollo 2015).
Tourist pressure appears to have driven declines in several island subpopulations, including the "large, important" subpopulation on Nueva Tabarca (Pollo 2015). Fire impacting Mediterranean scrubland, and urbanisation of the foothills, may be the major threat in interior regions of the species' range but any impacts on the species in inland regions are poorly-documented (Pollo 2015). Additionally, its distribution in these areas may be becoming increasingly fragmented due to intensive agriculture, roads, and forestry (Pollo 2015). Over 50% of the species' range lies within areas exposed to pesticide use, and it obtained the maximum possible value on the Exposure Risk Index for pesticides developed by Mingo et al. (2016) and above-average calculated Exposure Risk Factor as a function of this and its life history traits. These authors found that low-fecundity species were at elevated risk from pesticide exposure, and this species' small litter sizes may make it susceptible to any elevated mortality among neonates resulting from pesticide use.
The Ocellated Skink (Chalcides ocellatus) was first recorded in the Iberian Peninsula in 2017 (Bisbal-Chinesta et al. 2019), with residents' reports suggesting that the species was introduced to several sites in 2017 and 2018 likely with imports of ornamental plants (Pérez-García et al. in press). At present, it appears to be confined to the vicinity of country houses, gardens and plant nurseries, but is becoming more frequent and apparently more widespread (Pérez-García et al. in press). Should this exotic species become established in more natural areas it may pose a threat to the native skink (Pérez-García et al. in press).
Use and Trade Information
Although "illegal capture" is listed as a potential impact on island subpopulations by Pollo (2015), this species does not appear to be in trade to any significant degree.
Conservation Actions Information
It is included on Appendix II of the Bern Convention and Annex IV of the EU Habitats Directive, and it occurs in a number of protected areas. It is included in Annex II of the National Catalog of Endangered Species in Spain (Pollo 2015). Pino-Pérez et al. (2014) recommend legal protection and monitoring of continental subpopulations in the Cangas area of Galicia, and recognition of those throughout the Morazzo Peninsula as threatened. In order to ensure the survival of the major island subpopulations Pollo (2015) proposes management of the existing national parks encompassing Cíes and Ons islands, a marine reserve encompassing Nueva Tabarca, and the expansion of Southwest Alentejo and Costa Vicentina Natural Park to cover Pessegueiro. He also recommends habitat restoration for the benefit of this lizard. Pérez-García et al. (2022) recommend efforts to eradicate introduced populations of the ocellated skink and tightening regulations on the horticultural trade.